Personally, I think the UP Aqua atomizers are a POS, at least on anything larger than maybe a 10 gallon tank. Having tried the UP Aqua atomizer and now using the GLA atomic diffusers for 9 months or so, there is no comparison. The mist from the GLA diffuser is finer than that from the UP Aqua. Also, I could not adjust the flow rate with the UP Aqua diffuser like I could with the GLA because the ceramic that the CO2 is pushed through is thicker on the UP Aqua and I guess created more resistance.